Matrix is not XMPP version 2. Both protocols have very similar goals, but they have very different designs, and are developed by different people.
Both projects are active and one is not a replacement of the other. A third project with similar goals as Matrix and XMPP is Delta Chat - except instead of inventing a new protocol they are building on top of email.
All three systems are active open federated networks built around open-source software.@stefan